Interlocking balancing system



J. P. TARBoX. INTERLOCKING BALANCING SYSTEM.

APPLICATION FILED FEB. 7. 1913.

1,367,839, Patented Feb. 8, 1921.

6 SHEETS-SHEET l.

J. P. TARBOX.

INTERLGCKING BALANCING SYSTEM.

APPLICATION FILED FEB. I. IsIa.

1,367,839. Patented Feb. 8,1921.

6 SHEETS-SHEET 2.

@n uen/Lto@ /0 witnesses (7 f M @iw/AWM 551x I. P. TARBOX.

INTERLOCKING BALANCING SYSTEM.

APPLICATION FILED FEB. 7, 1913.

Patented Feb. 8, 1921.

6 SHEETS-SHEET 3- @vih/lewe@ 1. P. TARBOX.

INTERLOCKING BALANCING SYSTEM. APPLICATION FILE-D FEB. 7. |913.

1,367,839, Patented Feb. 8, 1921.

e SHEETS-SHEET 4. T- r E L E E l n vento@ J. P.` TARBOX. INTERLOCKING BALANCING SYSTEM. APPLICATlON FILED FEB. 7| i913.

1,367,839. Patented Feb. 8,1921.

6 SHEETS-SHEET 5.

l. P. TARBOX.

IIIII LOCKING BALANCING SYSTEM.

A P P L C A T l 0 N F l L ED FEB. 7| 1913. 1,367,839. 'Patented Feb. 8,'1921.

6 EEEEEEEEEEEE 6.

. ,UNITED STATES PATENT OFFICE.

JOHN P. TARBOX, 0F WASI-IINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO TARBOX SAFETY AIRCRAFT C0., OF WASHINGTON, DISTRICT 0F COLUMBIA, A CORPORA..

- TION OF DELAWARE.

Specification of Letters Patent.

Patented Feb.8, 1921.

Application led February 7, 1913. Serial No. 746,919.

To aZZ whom t may concern:

Be it known that I, JOHN P. TARBOX, a`v

citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Interlocking Balancing Systems, of which the following 1s a specification, reference being had therein to the accompanying drawings. My invention relates particularly to automatic balancing systems for air craft of the heavier than air type.v l/Vhile having this particular relation however, it will be obvious upon an understanding of'my invention that the same may be used as a whole or in part in connection with other types of air craft.

This system is an improvement upon previous systems in a large number of respects inasmuch as there are combined to constitute the system elemental governing rand controlling devices which collectively act to preserve the balance of the craft under practically every conceivable abnormal condition. The system further is possessed of a greatly increased operating efiiciency and regularity, uniformity and simplicity of operation. Y

The system is delineated for the most part diagrammatically in the accompanying drawings in which Figure 1A is a diagrammatic illustration of one-half of the same showing particularly that part 0f it pertaining to the lateral balancing ofthe craft.

Fig. 1B is a similar diagram showing that part of the system pertaining more particularly to the longitudinal balancing of the craft,

Figs. 2 and 3 are'perspective views of aeroplanes in iight showing the location of the governing devices on the craft.

Figs. 4 and 5 are front elevation and plan view respectively of an interlocking device of which I make use, and

Figs. 6 and 7 are diagrammatic illustrations of modified forms'of connections for certain governing devices applicable particularly to the control of longitudinal balance.

Fig. S is a diagrammatic illustration arranged in perspective of an embodiment of my invention excluding power operated mechanisms.

Fig. 9 is a similar view of another embodiment of the same.

Fig. 10 is a diagram showing a method of settlng up checking forces through the use of mechanisms of the type of F igs.v lA andr 1B.

Fig. 1l is a sectional detail of the valve 54 of Fig. 1A.

The systemincludes in combination both l longitudinal and lateral automatic balanclng mechanisms. The principal element in each of these mechanisms is in this embodiment of my invention a power operated position controlled motor device for operating ythe balancing rudders in accordance with the variance' of the craft from its normal position. These motor devices are designated generally M and N respectively. i

vReferring to Fig. 1?, the device M comprises primary and secondary Huid pressurel motors 10 and 11. While fluid pressure motors are shown and described, any other type .of motor may be used if desired, such for 1nstance as an electrical motor. The motors are reciprocating motors, comprising cylinders 12 and 12 in which are located pistons 13 and 13 which occupy normally positions centrally of the` cylinders. Their rods 14, 14 connect through connecting lever 15 with cord connections'l which are connected by intermediate means to lateralbalancing rudders shown in Fig. 1B.

Intermediate the cylinders 12 and 12a are two controlling valves, the one 17 of which controls the admission and exhaust of fluid from cylinder 1,2, and the other of'which 18 controls the admission of fluid and hence the application of power to cylinder 12. Cooperating with valve 17 are passages 19 which enter opposite .ends of cylinder 12. They terminate attheir outer ends in valve chamber 2O and are normally both closed by sections 21 of the piston valvey 17. Interme-4 diate the sections 21 fluid under pressure is admitted centrally of the valve chamber through a duct 22 from a source of pressure 23 or other source of power. The sections 21 of valve17 are inclined on their adjacent ends so that in the movement of the valve, the passage 22 is never closed.

The source of fluid .pressure 23 comprises in this embodiment a gear pump locatedl within a tank 24 and driven by a continuously rotating wind motor 25. This motor may-be of any type whatsoever. The wind in my copending application Serial Number A l engage teeth on block 'motor 25 may be located on any part ofthe vair craft where it is subject to wind pressure due to motion of the craft through the air. As long as the craft moves, this motor operates and drives the pump 23 unless it is disconnected from the pump by means of a clutch or stopped by other well known means. The pump circulates fluid under pressure through passage 22 and through the normally open by-passl 26 through which the circulated fluid ,is returned to tank 24.

Opening from opposite endsr of valve chamber 20 are exhaust ports 27 communieating with opposite ends of valve chamber 28 and normally closed by the two-part piston controlling valve 18. By-passes 29 connect the exhaust ports 27 normally-with a branch conduit 30 communicating with bypass 26. v The main controlling valve 17 of motor 10 is operated through bell-crank connections 31 with a reciprocable block 32 adapt-fl ed to slide back and forth in a slot 33 in'a relatively fixed support 34. The block 32 is .provided with-teeth in the manner disclosed 641,662. As clearly shown, there are two teeth on each side of the'block afa/different l distances from the center of the block in both 'vertical and horizontal planes. A surrounding frame- 35 reciprocable parallel to `the block 32 carries upper and lower inwardlyprojecting claws 36- 37 adapted to 32. One end 38 `of frame 35 is reciprocably pivotedtoa fixed point 39, while the other 40 is movable up and down about the pivot 39. An eccentric 41 mounted on a shaft 42 continuously driven as indicated by dotted line 43 from the wind motor 25, is connected by strap 44 and rod 45 to the end 38 of frame 35 to reciprocate the same.

V- The end 40 of the reciprocating frame 35 is pivotally connected reciprocably with one end of bll crank 46 pivoted to fixed point 47 and counterweighted` by the adjustable mass 48 on the oppositey side of pivot'47 from the arm 46supporting the weight of rframe 35. The-mass 48 is made sufficient to counterweight both the imposed weight of the endI 40 of frame 35 and the weight of the arm 46. Through the movement of bell crank 46 frame 35 may be moved up or down to reciprocate'the block 32 through the engagement of its claws 36, 37 with the teeth of block 32. l f

The secondary vcontrol `valve l18 is op-y erated through bell crank connection 49 with the'lost motion device connected with vpiston rod 14 of the primary motor 10. This lost motion device comprises a lever 50 pivoted closely adjacent the line of movement of -rection of their lengths.

piston rod'14v and having connected therewith rigidly av rod 51 projecting at right angles to the piston rodf14 and through a link v52 pivoted or swivelly connected therewith, whereby upon Vthe initial movement of therod 14, due to the close prox-` imity of link 52 tothe pivot of lever 50,

lever 50 is given a very large movement, and thereafter the rod 51 having been moved to a position approximately parallel to the rod 14, there is no substantial additional movement of lever 50. The operation of the lost motion device 50, 51, 52 is the same irrespective of the direction of movement of the lever 14. The lost motion device shown is of a well knownitype, and any other well known type may be substituted therefor.

to the arc-of movement of the end of lever` 55, this lever is automatically rdiseangaged from pawls 57-5'8 afterV apredetermined movement thereof and is returned to its normal central position and held there by oppositely acting springs 59, see Fig. 11. A

Connecting with bell crank lever 446 operating through relay 32-,35, is a standard of position responsive combinedly to variations in wind pressure and position of the craft from t normal. This standard comprises a pair of vanes 60-60 located respectively (see Figs. 2 and 3) at opposite sides of the craft. The vanes are mounted on substantially vertically extending axes-61 and have movement in unison thereabout. Preferably they lie inl asubstantially horizontal plane,

but they maybe inclined Dthereto in the di- In the direction of their widths, the vanes 60-60"` are inlclined to the horizontal, the portion thereof -62l on one side of the axes 61 being inclined oppositely to the portion 63 lying to the other side thereof/Thus under wind pressure in the direction offlight, air acting on portions 62 will tend to depress the vanes, while air acting on ortions 63 will tend to elevate the vanes. hus further under an upward draft of air the vanes'will tend to rotate in'one direction while under a downward blast of air they will tend to rotate the action of air either up or down at angles oblique to the vertical and varying in direction through the entire range from the horizontal to the vertical, there will result unbalancing of pressure withy respect to the opposite ends 62-63 of the vanes, giving in the opposite direction. Thus also under .i

rise to a torque about the axes 6l proportional combinedly to the direction of the Wind pressure and its amount. A

One end as, 63 of these vanes is made longer than the other, whereby there is normally as respects wind pressure in the line of flight or'air rush, an unbalancing ofthe same with respect to aXes 61 and a resulting bias of vanes 60-60 towarda position of least head resistance in which they are substantially parallel in length to the line of flight or to the air rush. This unbalanced condition may be brought about by other means such for instance as making the angle of inclination of one part as '63, different from that of the other partv 62 on the opposite side of the axis, orby increasing the width of the end 63l as respects the end 62, or in any other way increasing the surface projection of one side of the vane over and above the surface projection of the other in a plane normal to the width.

Rigidly connected with the vanes 60-60 through their axes 61 are longitudinally eX- tending arms 64 substantially parallel to thep line of flight and carrying each an adjustable weight 65 and an adjustable tail vane 66. As respects the arms 64 and the longitudinal axis of the air craft, the vanes 60-60 are positioned at equal and' opposite angles of Obliquity 'as clearly' shown.

They are retained normally in this position by connecting cords 67 between the opposite ends of the arms 64, being thus normally retained in said positions againstthe bias due to the unbalancing of the opposite sides 62-63 as aforesaid. Also through connections 67 they are compelled to move in unison.

One cord 67 connects with one end of differential lever 68 ofthe pair 68-69, while the other end of lever 68 is connected'with a vertical wind direction vane 70 mounted on a mast 71 centrally of the craft (see. Figs. 2 and 3). One end f lever 69 is pivoted to fixed point"72 as usual with this type of differential, while the other end connects through cords 73 with one end of lever 74. The opposite end of 74 is connected with bell crank lever 46, whereb primary control valve 17 is operated'.

counterbalancing weight 75 is Iadjustably connected with vane 70 whereby in lateral directions it is made free from the effects of gravity.

Lever 74 is centrally pivoted to lever 78 of a follow-up device comprising lever 76 and its connection pivotal point 77 to piston rod 14 and through lever 7 8 connected. at one end to lever 76 and at the other to a normally fixed lever 79.

Hand controlled lever 80 (see Fig. 1B) is connected by cord 81 to one end of lever 79, the lever 80 being provided with a latch ,sse

as shown for normally holding it in any 65 position -to which it may, be operated.

82 is in the vertical Steering rudder of the craft. It is connected by operating cords 83 and intermediate devices to a steering ost 84 Vprovided with a steering Wheel 85. oni70 nected with steering post 84 by cords 86 is a lever 87 pivoted at one end'88 to a fixed part and connecting at the other endby cord 89 with the end of the lever 79 oppositeto that towhich hand controlled lever 80 is 75 connected through cords 81.

The connections of steering post 84 to rudder 82 include a yielding means as a spring 90,l a lost motion connection 91 (shown as Geneva gears, although it may be of the type 80 vof connection 50- 451-52 above described), and a limit device 92; The yielding co nection permits movement of the steerin post 84 ineitlier direction without corresponding movement of rudder 82, while the lost motion device 91 as clearly shown permits a limited amount of initial movement of steering post 84 without motionof rudder 82, which during the initial movement islocated in its central position. The limit device 92 com- 90` prises a link 93 in series with cord 83, movable in opposite directions therewith andv 4having opposed abutting portions 94, 95. lCooperating With these portions 94, 95y are oppositely disposed abutments 96, 97 carried by 95 a shaft 98 mounted in suitable bearings parallel to link 93. Normally the stops 96, 97 do not project into thepath of abutments 94, 95, but by rotating the shaft 98, one or posite direction, stop 97 is projected into the' 110 y path of abutment 9V Also coperating with abutments 94, 95 is a second limit stop device comprising oppositely disposed lobes 102 of variable radius `mounted to be rotated on pivot 103 in the line 115 of movement of abutments 94, 95. The limit device 1,02 is connected through cords 104 to be rotated in responseto variations in wind pressure upon pressure responsive device 105 (see Fig. 1B). In this embodiment this pres- 120 sure responsive device comprises a'geometrically plane surface mounted to move about a laterally extending horizontal axis 106 (see also Fig. 2) and normally occupying a position of substantially 45O inclination to the 125 horizontal. That particular angle should be chosen which will give the best range of regulation as this can readily be determined by reference to the characteristic curves of the particular surface 105 used. This device is biased' forwardly against wind pressure by a spring 107. Instead of the device 105 just described, any of the pressure responsive devices now well known in the ar/tl may be used and connected to impart motion through cords or othr transmission 104 to limit device 102 in response to variations in wind One of the devices now well known to the art is shown in Fig. 3 and comprises a lifting surface 108 pivoted at its forward end to a laterally extendinghorizontal axis 109 and biased downwardly against the lifting force of the air by springs 110. Through cords 104 connected with the axis 109 or in any other way with the surface 108, the motion of the surface of 108 is communicated to limitdevice 102.

The power .operated motor mechanism comprising primary and secondary motors 10 and 11, is connected through cords 16- 16 as aforesaid with balancing devices 111 shown in the form of -ailerons or lateral balancing rudders.

a latch to hold it in any adjusted position" similar to the lever 80 if desired.

Also mounted on the air craft', and/oper- Instead of connection to` the ailerons 111, connection may be made to other forms of lateral balancing devices such' vanes -60 as is the mechanism-'10-11, the mechanism 117 is governed combinedly by the pressure responsive device 105 and a gravity controlled standard ofy position 125. This gravity controlled standard of position is as :'hown of the pendular type, and is mounted on a relatively fixed pivot 126. `The controllingrforce is derived not through a weightbut through a balloon or air oat 127 aflixed to the upper end of the pendulum'rod. Weight 128 at the`lower end thereof is adjustable and for the purpose of counterbalancing theweight of the device 127 and the `rod above pivot 126, whereby the standard of position is undisturbed by -forces applied through its pivotal point of support 126, for the pivotal point 126 then .constitutes the centroid of the dev1ce.

. Any known type of standard of position with respect to the earth, such as pendular, gyroscopic, etc. may be substituted therefor. This gravity controlled standard of position is connected to one end of the differential lever 129, which lever is connected at its other end through link 130, with pressure responsive device 105, and at an intermediate point through link 131 with the lower end of lever 174 of mechanism 117 whereby they(` combined movements of the pressureo re-A f sponsive device 105 and of the craft with respect to the standard 125 govern the operation of the horizontal rudder 121 through mechanism 117.. A separate device 105 may be used for this government of mechanism 117 if desired, but it is convenient to use for thisvpurpose the same one which operating in a plane substantially at right angles to the motor mechanism 10-11 previously described, is a second motor mechanism essentially the same as the motor 'i mechanism10-11 and designated generally 117. This mechanism insteadfof operating lateral balancing devices 111 through connections as cords 16, etc., is connected by link 118 to one lever 119 of (differential i 119-120 tov operate the horizontal elevating rudder 121 which is connected to one end of lever ,120 by operating cords 122. The end of lever 119 opposite link'118 is connected to a fixed point, while the end of lever 120 opposite that connected to cord 122is connected by cord 123 to operating llever 124 of a hand controlled devicesimilar in all essential respects to hand lever 116 for operating the lateral balancing devices 111.

ates the limit device 102.

Also connected to pressure responsive device'105 is a second limit device 132, connection being made by cords 133. (Limit device '132 comprises an eccentrically mounted substantially circular disk adapted to be revolved about its axis 134 when the pressure responsivev device 105 moves. -Inments 94-95 in cord 83 connecting with s the vertical rudder 82. These abutments v are in theplane/of the disk 132 and when The motor device 117 differs from the de- 4vice 10-11 only in that the means for. govthe lever 124 is moved back and forth to operate the horizontal rudder 12.1, the disk 132 limits the movements thereof through the engagement ofthe abutments`135-f136 l with the disk 132.

Also coperating with thelimit` device 132 is a second pair of limit stops 137-7138 included in series with an operating cord 139 connecting with a manual operating lever '140 and also'with the lower end of the folthe lever 176 may be adjusted by hand to f with locking means shown or not as desired.

' Throttle lever 144 is connected through dif- At vthe top of Fig. 1B is shown the propelling engine 141 together with its throttle or other power controlling device 142. Thisthr'ottle is biased to open position by a spring 143 connected to the lev'er 144.

ferential lever 145 with a direct foot or hand control. lever 146 through cords 147.

Additionally from the opposite end of differential lever 145 throttle lever 144 is Jconnected by cord 148' to one end of lever 149 of the set of three differential levers` 149--150-151. Lever 149 is pivoted centrally upon lever 150, one end of which is pivoted to a fixed point, while the other end is connected centrally of lever 151. Lever 151 is connected at its upper end to pressure responsive device 105 `through operating cords 133 of the vlimit device 132, and at its lower end to manual operating lever 140 of the mechanism N through cord 152. The opposite end of lever 149 from that connected to cord 148 is connected by cord 153 to a normally centrally positioned arm 154 onv the steering shaft 84. A spring 155 biases the upper end of lever 149 to the left, thus keeping the cord 153 under tension. The connections shown are principally dia- 'grammatic and obviously the parts may be connected together in the same operative relation by any one of a number of well known means. Besides being connected to the throttle lei ver 144 in the manner just described, the

pressure responsive device 105 has interconnection with two other parts of the system. Through extension 156 from cords 104 connecting with the limit device 102 of the vertical rudder 82, connection is made with sliding block 157 in slot 158 of lever 87, the' block 157 being biased to one extreme position by spring 159 and being moved back and forth therefrom through movement of cord 156 by pressure responsive device 105. The block 157 connects directly withcord 89 previously descrild as connected with lever 79 of motor mechanism 10--11. Lever 79 is kept in normal position, and cord 89 permanently connected by primary cord 16 to the yoke lever 15 of thev mechanism 10-11. Secondary cord 16 connects directly with block 162 whereby when the block 162 is moved back and forth from its@ j power as described, we assume that the craft extreme position to which it is biased by spring 166, the amplitude of movement of lbalancing devices 111 through secondary Supplying powerto the mechanism 117 which operates the horizontal rudder 121 is' a second pumping system similar to that shown in connection with the motor mechanism 10-11. This mechanism is designated generally 167 and as indicated by dotted line 168 is driven from the same wind motor 25 which drives the pump 23.

As thus described, the operation of the mechanism of my invention and of the method thereof is as follows:

The wind motor 25 which operates at al substantially constant speed under a substantially constant wind pressure, drives the pumps 23and 167 continuously, circulating operating fluid for the motor mechanism 10-11 and 117 respectively through the passages 22 and 26 in series, the fluid passing ,centrally of the valve chamber of the primary motor 10 as shown in Fig. 1A. As will .appear later, the wind pressurein the line df flight is maintained `substantially constant through the governing action of the pressure responsive device 105 alone, or in com- 4 bination with the governing action of the vanes 60--60 which are also responsive to pressure. sive device 105 governs the speed of operationof the wind motor 25 and hence the rate of circulation of operating fluid through the motor mechanism. By means of thumb screw 109?, the action of the pressure responsive device may be adjusted, whereby the normal wind pressure is determined, and consequently the speed of wind inotor 25 is adjusted up or down as desired. This takes place for the reason that for each operation of spring 107 of the pressure responsive device 105, an increase .or decrease of normal wind pressure is necessary to retain pressure responsive device 105 in its normal position.

The speed of the wind motor. 25 may be"` additionally regulated by throttle valve 169 in supply conduit 22, or any equivalent means associated with the motor mechanism. The point of prime importance is however, that due to the governing action of the pressure responsive device 105 the course of the craftis so directed that the Wind pressure on the motor 25 is maintained at a substan- Therefore the pressure respon` tially constant value and it may be counted upon to supply power for the motor mecha.- nisms 10-11 and 117 at a determinate rate.

lVith the wind motor operatlng to supply is traveling at its normal rate against wind tion occurs on one side of the craft or the other is `of no moment as respects the resulting accurate corrective action of this system. As previously explained, the action of wind pressure on either of vanes 60 or 60 which are located as shown in Fig. 2 at opposite lateral extremities of the craft, in any direc- ',tion other than normal, produces resulting motion of the vanes 60-60 about their axes, except under one condition, and that is A that the vvariation in wind pressure is the same in amount and direction on both of the vanes 60-60. If the direction of the wind pressure is normal and in the 'line ,of

jlight, but is greater on one side of the craft than the other, say on the side of the vane 60', then the vanes become unbalancedas respects each other, and there results movement in unison about their axes. In the instance chosen, the increased pressure of the vane 60 causes a rotation of the vanes 1n a counterclockwise direction (looking down on the system fromabove), for it is the right hand end 63 of this vane which is of the greater surface area. This eounterclockwlseimovement continues until the angle of ,control the operation of theobliquity of 'vane 60 to the longitudinal has been decreased and that of the vane 6() increased to make the unbalancing pressure on the end 63 of vane 60 equal to the momentarily increased unbalancing pressure o n the end 63 of vane 60. The action of the l'commonly known 'kite vis simulated in the action of these connected vanes which move 1n unison, and bearing the action of the kite in mind, the action of these vanes in this respect will be fully understood. An entirely s1m1lar action takes place when the wind. pressure is increased on the side of thevane 60, the vanes then moving in unison clockwise instead of counterclockwise. Thus as respects increase of wind pressure on opposite sides of the craft, the resulting movements,y of the vanes 60-60 are opposite. This is exactly what is neededrto directively n balancing devices 111 of the craft.

The above described action is the simplest action of the vanes 60-60 under variatlons of wind pressure. A moments further consideration will show however, that the character of the vanes 60-60 and their mounting is such that their action even under the most complex variations in wind pressure is accurately directive of lthej `ment of the vanes by reason of the counter- .clockwise torque which the upward wind pressure imposes on vane 60. AThis torque if the upward windpressure' be vertical is exerted combinedly on both ends of vane 60', for the reason that the end 62 is oppositely inclined as respects end 63. 'There is thus attained the very strongest" torque under these conditions of great disturbance. If the upward wind pressure be at any angle less than the vertical, there is still a counterclockwise torqueon each end -of the vane 60 until the direction of the wind pressure coincides with the plane of the end 62 whereupon the counterclockwise torque is exerted through the end 63 only. And between this direction of wind pressure, and

f the direction of flight, the counterclockwise torque is decreased as the direction of the unbalancing pressure approaches more nearly to the direction of flight, the wi-nd pressure on end 62 opposing the preponderating wind pressure on the end 63. The reverse is true, of upward pressures on the vane 60 on the opposite side of the craft, the vanes being moved clockwse instead of counterclockwise.

TheV action of the vanes 60-60 under downwardly directed wind pressure'is substantially similar tosthe action under upwardly directed wind pressure with the exception of the fact that the movements thereof are exactly opposite under downwardly directed pressure from what they are @under upwardly directed pressure'. Thus downwardly directed pressure on vane 60 results in a clockwise movementof the vanes instead of a counter-clockwise movement, and downwardly directed pressure upon vane 60 results in a counterclockwise movement instead of a clockwise movement. Under variations in the direction of wind pressure between vertical downwardly directed pressures and wind pressure in the line of flight, the action isl the same with the exception that the resulting torques produced on the vanes 60-60 are proportionately' reduced as the wind pressure approaches the line of Hight. In this case as in the case of vertically directed upward pressure, the directive torque on the vanes is greatest when ythe wind pressure is approximately vertical adjustable masses 65 onthat side of the axis 'of each vane, the vanes 601-60 swing in unlson clockwlse.

Upon an unbalancing of the craft resulting in the lowering of the side 'of the vane60, the reverse is true,

.. gravity effecting counterclockwise movement against the wind.

In initial response to pressure variations and in subsequent response to changes of the craft to vits normal position, the vanes 60-60 fly with the wind, so to speak, moving in unison always to a position defining ythe direction of wind pressure upon the craft: lVhen this movement takes place,.it is not desired that the balancing devices 111 be operated, unless there is at the same time change in Wind pressure as respects the opposite sides of the craft. By reason ofthe connection of the vanes 60'-60 with the verticall wind direction vane 70, through the differential connection 68-69, mere movement of vanes 60-60 to accord with lthe direction ofthe wind in the plane of fiight, is prevented from directing the operation of the balancing devices. This is because the arrangement of .the differential permits movement of vanes 60 -60 under these conditions to be annuled by a precisely proportional'movement of the wind direction vane 70 which always vflies with the wind. y,Since the vane 7 Oxis centrally located, it is not subject to the variations in wind pressure at the lateral extremities of the craft, and since the 'vane is vertical even if in a position. to be subject to a change in pressure, the effect on 'it would be quite small in comparison with the effect on the specially devised vanes 60-60. Furthermore being counterbalanced gravitationalfly by mass 75, it is not subject to movement due toa change of the a normal position of the craftz Thus the directive control of vanes 60-60 Lis not impaired in any way through change of direction of windpressure in the horizontal plane of the machine. The compensating vane may or may not be used as desired, and in air craft where the speedof travel is yery lhigh and in calm weather where cross winds of great velocity are not encountered, the device will be wholly unnecessary. In such case the interconnecting cords 67 of the vanes 60--60 are connected directly to the lever 74 of the power operated mechanism anl the ldifferential connection 68-69 omitte crank 46 is moved to right or left,'resulting in the operation of the power controlling valve 17 of the mechanism 10-11 to righ-t or left as above described., Now assuming that movement of the vanes 60-60 andiunder one of the disturbing conditions of wind pressure previously described is clockwise, lever 74 is moved through connection with cord 7 3 from the differential 68-69 counterclockwise about itspivot on lever 76. I Bell crank 46 is moved thereby clockwise 'raising the erfd 40 of the `frame 35 and thereby. effecting a right hand movement of the block 32 and a resulting right hand movement of valve 17 in chamber 20. The normally open by-pass 26v is thereby closed by the left disk of the valve* 17, and the right hand port 19 to the motor cylinder 10 Ais vice 1.11 being moved upwardly (looking in the direction of flight). As will be seen this will result inl raising the left of the craft and lowering the right of the craft. Under all conditions, moving the vanes 60-'60 clockwise, the left side of the craft is the relatively depressed or lowered side, and it is therefore seen that the directive action of l the vanes 60-60 upon the operation of the balancing devices 111 is correct.

Upon the initial movement of the rod '14 to the left lresulting in the aforementioned movement of the balancing devices' 111,

through lost motion` connection 50--51-52, V valve 18 of the secondary motor`11 is moved to the right, closing left hand port 29 andv opening right-hand port 27 from the valve 20 of the primary motor 10. During continuation of movement of the piston rod 14 to the left however, no further movement of the valve 18 takes place, for the reason .that almost immediately after the initial movement of piston rod 14, rod 51 of the lost motion de,-

vice is substantially parallel to it. During this time however right-hand port 27 is covered by the right hand disk 21 of valve '17. Thus no fluid may pass through righthand port 27 and into secondary motor 11 through the uncovered port 27 leading to the left hand end of the motor cylinder.

The balancing devices 111, having been moved to a point where the corrective force established is sufiicient to check the disturbf -ing force of the craft, or check the unbalanclt is apparent that through the move-v ment of lever 74 to right-or left, the bellJ ing movement thereof, the follow-up mechamsm having prevented over movement and the'craft then returned toward normal position, vanes 60, 60 move therefore in the return toward normal counterclockwise, and through the connection with lever 74 reverseA ,they/ were moved from normal.

the position of valve 17, moving it first to its central position as shown and thereafter (by reason of the abnormal position of the follovs7 up levers 76, 78) to its left hand position' in which the right hand port 19 communicates with the noW open right-hand port 27'A leading through passage 27 to the left-hand end of secondary motor 11, and in which left hand port 19 of the primary motor 10 is -left hand passage 27 to the left hand end of secondary motor 11. The piston 13 and piston rod 14 are thereby moved to .the right. This motion to the right is the same as the return motion of the piston rod 14 of the primary. motor 10. The result is that through the common connection 15 and the cords 16--16, etc., the balancing devices 111 are subjected to the combined action of the. primary and secondary motors in the same direction. They therefore return toward normal at a rate greater than that 'at Which This in- 'creased movement of the balancing devices continues until the balancing devices have reached normal and have been moved past normal, thus setting up checking forces in the opposite-direction. which checking forces meets the inertia of the craft as it comes and there is a freedom from unbalancing rapidly into normal position and stop the craft precisely at its normal position.

When the craft. is in its normal posltion,

conditions, the vanes -60 are in their normal position. and through the lever 74, the valve 17 of the primary motor is moved to .occupy the central position as shown. In this position of theI valve 17 and with the craft at normal. the piston 13 and piston rod 14 of the primary motor are always in the lnormal position `shown. Therefore as the craft reaches its normal position and as piston 13 and rod 14 take 'their-normal positions, the rod 51 of the lost motion device 50-5152 is given a relatively great movement, returningr` the controlling valve 18 of the secondary motor 11 to its normal posivtion in which the transfer of fluid from the right hand end of the primary motor 10 to @the left of the secondary motor 11 is cut of through closure of ports 27-27. As these ports are closed, the by-pass ports 29' are opened and such small amount of remaining exhaust fluid as may pass from primary motor 10 is forced through ports 29 and branch 30 in the return conduit 26 of the fluid sup- -it moves under gravity control alone for ply system. This stops all movement of the secondary motor 11 as the motion of thelprimary motor 10 is stopped. During the return to normal movement of the valve 18 of the secondary motor, the by-pass valve 54 of the secondary motor is opened momen- 7 tarily through the engagement of lever 55 With the left hand clayv 57 in the left hand movementof the valve 18. An immediate return of the secondary motor to normal position and with it the balancing devices 111 is effected. The lever 55 by reason of its arc of movement becoming disengaged from the claw 57, thel valve 54 is, again closed in itscentral position by springs 59. The return to normal movement of piston 13 and the balancing devices 111 is augmented through the provision bf springs .13 in opposite ends of the motor cylinder,

or their equivalent. Thus the checking force is removed just as the craft comes to rest in its normal balanced position. With ailerons 111 of the type shown, the springs l13 are not of much utility, but with ailerons of What may be termedd the balanced type having no bias to normal under vWind pressure, the springs 13" may have all of the Work of the return to normal to do.

U1 Upon an unbalancing movement of the craft vin the opposite direction, due to'any cause which effects Acounterclockwise movement of the vanes 60-60, the operation of the mechanism just described is precisely reversed, The valve 17 is initially moved to the left instead of to the right, thus closing the left-hand port 27 instead of the right, leaving theright open as Was previously the left 4for the exhaust of fluid by Way of branch 29. Thevalve 18 in the initial righthand movement of the rod 14 is set over to` the left, thus opening up the left-hand port 27 to the port 27 of the right-hand end of the secondary motor 11. The previously described actions vvill follow in order.

fact that upon the return of the craft to normal from such resulting unbalancing position as it may have taken, a checking force is set up through the primary and secondary motors 10-11 as just described, the balance of the craft is very accurately preserved, and'at no time is the movement o f the craft from normaland its return thereto exces- Asive or severe. TheNv craft does not move from its no-rmal position With such a system of balancing to nearly such an extent as the reason that through the pressure responsive vanes 60- 60 there is an anticipation of the movement, which movement while it may be not altogether' prevented is always held toa minimum.

At this point it should be noted that when the craft does become unbalanced and the greater mass of end 63 and weight 65 affect vanes (S0-60. their movement continues only until theA deflecting component of the` weights which is proportional to the angle of unbalancing is counterbalanced by an increased wind pressure on the end 63 of the vane on the relatively low side. The wind pressure on the ends 63 of the vanes increases relatively when either vane is given of the craft about a longitudinal axis, the i horizontal rudder 121 operated by mechanism 117r` maintains the longitudinal stability about a transverse axis. As respects the mechanism 117 and its connection to the horizontal rudder 121 a sufficient description has already been given to enable its operation to be clearly understood from the described operation of the mechanism 10-11. There is this to be noted however, that in general construction the mechanism 117 and its connections 'to the horizontal rudder 121 differ from mechanism 10-11 and its connections to ailerons 111` in the omission of cord connections 16-16, vand the provision of a simple link 118 between the yoke lever 15 and the lever 119 of differential 119-120 which connects with `the rudder 121. As is the case' with ailerons 111 which are manually operable through lever 116 and differ'- ential lli-413. the horizontal .rudder 121 is similarly manually operable through lever 124 and differential 119-120.

The difference of prime importance between the operation of the system directed particularly to the maintenance of lateral stability through the operations of ailerons 111 and that portion of the system directed to the maintenance of the longitudinal stability. is to be found in the government of the 'latter portion of the system through pressure responsive device 105 and gravity controlled standard 125 instead of `through a set of vanes (S0. 60. This difference exists because of the difference in conditions to be met.

In the maintenance of lateral stability we are dealing with unbalancing caused principally b v differences in lift moments of the 'ments as between the right and left wings of the machine brought about by changes in velocity and directions of air rush, and with differences in lateral load distribution; whereas in longitudinal stability we deal with differences in lift moprincipal supporting surface and the tail of the machine, with changes inload distribution with respect to the center of lift, with changes i resulting shifts of the center of lift itself, with critical angles of lift, critical speeds, soaring conditions, etc. Obviously these conditions yare not only greater in number, but different in kind.

Upon a sudden increase in wind pressure on the device 105, it is moved rearwardly carrying with it the lower end of lever 129 and through link 131 operating lever 174 counterclockwise, the bell crank 46 clockwise, and the valve 17 to the right of the diagram, thus effecting the movement of piston rod 14 to the left with a resulting movement ofy levers 119-120 to the left, thus raising the horizontal rudder 121 and pointing the craft upwardly. Exactly the reverse takes place upon a marked decrease in pressure, the horizontal rudder 121 being deflected .downwardly. Due to theaction' of the follow-up lever 176 (and this action is the same for the mechanism 10-11 as for the mechanism 117 at present under consideratiom) the rudder 121 is not moved to the full extremity upon each operation of the mechanism 117, lever 176 after a degree of movement depending upon the position of lever 174, moving that lever about its point of connection to link 131 to give the valve 17 its mid position whereupon operation of mechanism 117 ceases until there is further variation one way or the other of the governing devices 105 and 125. Its follow-up action is well understood and needs no detailed description herein. Thus it will be apparent that the climbing angle of `the craft is regulated automatically 1n accordance with the wind pressure and since wind pressure depends directly upon the propelling power and speed of the craft the angle of climbing is likewise proportioned to the speed. When the y speed is sufficiently great to warrant climbing at a greater' angle, increased wind pressure upon device 105 operates they horizontal rudder 121 to point the craft upwardly. lV hen the speed is too low for climbing, a decreased wind pressure on device 105 effects operation of horizontal rudder 121 to point the craft downwardly at a suitable angle for safe flight. and under conditions of extremely low speed at the proper angle forsafe descent. An air craft climbs best when the climbing angle is adjusted to suit the particular speed at which the craft is traveling against the wind, and for each different speed the mostefficient climbing angle is different. The adjustments to the different in incidence,

speeds are automatically and continuously taken care of by the governing action of the vpressure responsive device 105.

- t the speed through manual adjustmentof the throttle lever 146 lof the engine, or through the use of the manual control lever 140 connected with the follow-up lever 176. When the lever 140 is adjusted, it gives to lever 176 a new normal position as respects the device 105, and through the resulting operation of the rudder 121, gives the craft likewise a new normal positionas respects the normal position of device 105. movement alters the speed. l Thus when it is desired to climb the maximum distance in the shortest time for a given speed, the lever 140 may not be disturbed, and the device 105 will automatically effect climbing at the very highest rate. At any time whatsoever however, through lever 140, the normal direction and rate of travel of the craft in the vertical plane may be adjusted by simf ply moving lever 140 to the desired position. Lever 140 and its connections, with followup lever 176, thus constitute a most eflicient means for steering the craft through the power operated mechanism 117.

\ Should the power operated 'mechanism 117 become disabled due to any-cause, the rudder 121 may be controlled directly through le-` .aver 124 which connects directly therewith through differential 119-120. There isno class of control left unprovided for. Should `the pilot desire air rush control alone, he

may lock out the earths standard 125 by use of device 1252 should he desire earth?s pos1- 'tive control alone, he can lock out air rush 'control device 105 by device 249, and should l' position of the craft, but of the position of the rudder 121 itself at any instant. When the mechanism 117 is under control of standard 105, the manual control 124 may be used surface 105 forwardly in-response to a desimilarly t`.o manual co1r1trol140.I

The set of levers 80 and 116 associated with the mechanism 10-11 are provided for the same purpose as are levers 140 and 124. Through movement of lever 80, the ailerons This, like the throttle' lin degree of wind pressure without 111 may be operated through mechanism 10'-11 to alter the normalangle or lateral balance lof the craft, while through lever 11G ailerons 111 may be operated in supplement to operation by the power driven mechanism 10-11 or independentlythereof should that mechanism become disabled..

To return to the pressure responsive control device 105, not only is this device responsive to variations in the degree of wind pressure, but it is also responsive to variations in the direction of the wind by virtue of the angle of inclinationl of its surface. Thus it compensates for changes in lift and travel of center of pressure under varying angles of incidence. When the direction of v 121 to point the craft downwardly against the unbalancing action of the upwardly directed wind pressure. Conversely, a downwardly directed wind pressure approaches the normal to the surface 105 'instead of parallelism therewith, with the Iresult that there is an increase of total pressure on surface 105 and the surface is moved rearwardly proportionally to the variationA in the angular direction of the wind, -causing pointing of the craft upwardly against the downwardly directed unbalancing pressure of the wind. The operation of the mechanism 117 under these conditions is the same as under preceding conditions of change change in direction.A f

Still further. through device 105 the craft equipped with Vthis system is adapted for soaring. Under conditions of prolonged alteration of the normal direction of the wind, the device 105 positions the craft properly for soaring thereupon. Thus assuming that the direction of theV wind is upwardly as it Ashould be for soaring flight, immediately the direction of the wind changes, the total pressure on surface 1051s decreased with the `result that rudder 121 is moved to point the craft downwardly and more closely into parallelism with the direction ofthe wind. This downward movement continues until surface 105 is given its normal angular position with respect to direction of the wind. This normal angular position -is attained when due to the combined movement of the .crease of pressure, and the pointing o'f the craft downwardly, the pressure on surface 105 is increased and surface 105 is moved rearwardly as the craft continues to point downwardly, thus restoring rudder 121 approximately to its normal position, under which conditions the craft is pointed into the teeth of the upwardly directed wind in which case as is well known, the craft will move against the wind with less or without any propelling power depending upon the degree and ydirection of the wind. The reason for this is that the direction of the total force on the planes of the craft is forwardly of the vertical under these conditions and it has a substantial horizontal component. Obviously having positioned thev craft for the soaring flight, the device 105 adjusts its position for each subsequent variation ofthe wind.

Through the thumb screw 109a and the spring 107, the governing action of the` device 105 may be adjusted under these conditions with great fineness. Also when atmospheric conditions are suitable for soaring flight at frequent intervals, it is best to cut out the gravity controlled standard of position 125 so'that the pressure responsive device 105 may act independently thereof.

In order that this may be accomplished, a.

lock 125a is provided in the form of a bolt mounted to turn in fixed bearings 125* and provided with normally vertical arms 125c adapted when `the bolt is turned to take a horizontal position in the plane of movement of the pendulum 125 and'one on either side thereof. f

' Adjustment ofthe angle of incidence for soaring Hight may also be-had through lever 140 by moving it the desired degree asv previously described in 'connection with steering in the vertical plane. "Any alteration in the position of the lever 140 alters the angle of incidence of the craft with respect to the` normal directionof the wind. Between the adjustment 107-109@ and the adjustment through lever 140, the position of the craft may be adjusted with the greatest accuracy.

Through their various interconnections'as well as through the interaction previously described, the mechanisms 10-11 and 117, coperate with each other to produce a number of important results in addition to those already specified. The first one of these to be'mentioned is the automatic adjustment of the degree of manual direction of the craft from normal at any instant in accordance with variations in wind pressure. This is accomplished through the connection of the pressure responsive device 105 with the limit devices 102-132 associated respectively with the vertical rudder 82 and the horizontal rudder 121. The position of each ofthese devices 102 and 132 is varied exactly in accordance with the variation 1n wind pressure upon device 105.

Upon increase of wind pressure on device 105 limit device 102 is rotated to -interpose portions of decreased radius between the abutments 94 in the operating connections 33 to the vertical rudder '82.` The result is that vertical rudder 82 other hand, during low speed conditions,v

when the wind pressure is comparatively low,

short turns should not be attempted.

Low wind pressure on device 105 results in the movement of limit device .102 to interpose portionsof increased'radius between stops 94 and 95with the result that the angle of turn is decreased in proportion to the decrease in speed. For each speed, the limit device 102 is therefore adjusted tor-permit the maximum safe, angle of turn.

The device 132, it will be noted, is of substantially uniform radius, but by virtue of its eccentric mounting, 'its position as respects stops 137138 and 135-136 is varied, thus altering not the degree of movement of the horizontal rudder 121, but altering the range ofvmovement thereof, defining by its position the position of the range of movelment of the rudder/121. ByA following out the connections it will be noted that under conditions of increased wind pressure'obtaining under hlgh speed, the rudder 121 may 4be moved u )wardl .a considerable distance thus permitting a sharp turn upwardly to be made, while under conditions of low pressure obtaining at low speeds, the rudder y121 may be pointed upwardly but a very small degree if any at all. Under conditions of the very lowest safe speeds, the position of the device 132 will be such as to prevent either lever 140 or lever 124 to be moved to a position to point the craft upwardly. -At the' same time they may be moved freely to direct the craft. downwardly in any suitable volplane to earth.r Either or both of these sets of stops 137-138 and 135-136 may be omitted if desired.

Vhile the devices 102-132 are shown separately in the diagrams of Figs. 1A and 1B, as shown in Fig. 4, it is intended that they be mounted on a Common spindle 103 and operated by a common connection 104 lwith the pressure responsive device- 105. As shown in Figs. 4 and 5, the spindle 103 .is mounted vertically on a rectangular abutment 95.

sheet material as for instance sheet aluininum and will weigh but a few ounces. Since connections 83 to the vertical rudder and connections 123 to the horizontal rudder usually parallel each other as installed on a machine, it will be seen that the combination of these limiting devices in a single structure is a feature of marked economy.

`Also combined .with the limit devices 102 and 103 in the frame 170 is a locking device 96-97-98 operated from lost motion device 50-51-52 (see Fig. 1A) of mechanism 1011'. This device comprises a shaft 98 substantially parallel to the bar 93 and provided with outwardly yielding abutments 96-97. Upon each initial movement of piston rod 14 and hence of the balancing devices 111 from their normal positions, the shaft 98 is rotated in one direction or the other to interpose either stop 97 in the path of theabutment 94 or stop 96 in the path of The interposition of these stops in this manner .positively prevents movement of vertical rudder 82 to make a turn in a direction opposite to the then prevailing direction ofunbalancing of the craft. lThe need for such provision is yvell known. Not only should the Vcraft be u 0n an even keel when a turn is commenced, ut it should more preferabl be banked on the off side of the turn. his locking device insures the craft being upon an even keel before any turn can be commenced. ,Of

course adjustment of lthe device may be made on one side or the other so that lthe turn may be commenced a little before or not until a little after the craft has reached its normal position, this being merely a matter of degree, the essential featurefof my invention being that the craft must be 'brought substantially to an even keel before a turn may be commenced.y If the skilled pilot desires it, the device 96, 97, 98 may be omitted.

Due to the 'provision of the inwardlyv possible when the vertical rudder is moved suddenly to make a Ishort turn, the opera- -tion 0f the balancing mechanism 10-11 lagging slightly behind it. It is especially to benoted that the stops 96-97 are at 180 with each other, and that due to this only ,onel of them is effective at a time. That one is the one which prevents turning in a vdirection away from the low side of the craft. Turning may be freely exercised in the direction of the low side. i

It sometimes happens that turning away from the low side of the craft judiciously assists in restoring the balance of the craft.

'ment of rudder 82 through the It is contemplated that the automatic `in this system between the locking device 102 and the vertical rudder 82.

The connection 86-87-89 from steering post 84 to lever 79 is made for the purpose of initially banking the craft prior to making a turn.A Between the connection 86 and the ylocking device 102 are provided the yielding connection 90 and the Geneva gearing, which not only permits movement of lever 79 tov set the mechanism 10--11 to bring about the desired initialangle of bank,

but also permits the steering post 84 to be moved to Whatever position it is desired to give the rudder 82 irrespective of the then position of the stops 96-97. The steering post 84 being retained in its position, im-

, mediately the craft has turned substantially to vnormal and stops 96w-97 have been returned to their normally disconnected positions, the spring effects the desired movement of the rudder 82 by virtuekof its potential energy. Thus the operator is not disturbed by sudden bringing up of the steering post due to the abutment` of stop 96 or 97 with 94 or 95.` The angle of bank having beenv 4 previously determined through the prior operation of lever 79, the sudden movepotential energy of spring 90 is all right.

When the pressure responsive device 105 moves, it also operates the block 162 (see Fig. 1A) Yup and down in slot 163 to effect the amplitude of movement of the ailerons 111 in accordance with thewind pressure and hence with the speed `of the craft. Obviously under high speeds a smaller amount of movementbf the balancing devices is vcraft as by the` power of the `gust which strikes the machine andthe corrective forces set up by the balancing-devices 111 shouldtherefore be maintained substantially con; stant. This is done throughv the connection of block 162 with the pressure responsive device 105.

A similar connection' may be provided and is contemplated according to the present invention for the horizontal rudder 121. Since in operation and in result its action is' identically the same as that shown in connection with ailerons 111, it is not deemed necessary to duplicate the showing.

Through connection 156 `in extension of connection 104, block 157 carried by lever- J high speed, a high angle of bank is both safe and necessary. This feature of the system is not important in all cases and may be used or not as desired. The device 102 controlling the degree of turn of course incidentally controls the degree of bank.

Through the connection of device 105 with lever 151 of differential connections 149- 150-451, the throttle is opened and closed in accordance with variations in wind pressure. Thus under disturbing atmospheric conditions, the speed is increased or decreased as may be most desirable to force or retard the cra/ft in its movement through the disturbed space. Through variations in the lengths of the lever connections to the throttle 142, the degree of such variation maybe made as small or large as desired. As now connected, the throttle is automatically opened more widely under conditions of low pressure and automatically partially closed under conditions of high wind pressure. The degree of such opening and closing is of course small asl respects the full movement of the throttle. The propelling power is varied accordingly.

The vertical steering post 84 also has connection through differential 149-150 with the throttle 142. lVhen the post 85 is moved to the right or to the left to initiate a turn,

thethrottle is opened slightly to increase the propelling power and give increased stability due to increased speed in making the turn. The speed of air craft always falls away during balancing operations, and due to the falling away-of the speed and the consequent decrease in efficiency off the balancing devices and steering rudders, the preservation of the balance is rendered more difiicult. Through this variation of the propelling'power in accordance with a function of the degree of movement from normal, the speed of the craft is maintained substantially uniform despite the unbalancing "movements and during the most rapid succession of turns..

Through connection of control -lever 140 with differential 149-150-151, the throttle is opened when lever 140 is moved to steer the craft upwardly and closed when lever 140 is moved to steer the craft downwardly.

The degree of this movement is preferably ment pertaining during movement of p'ressure responsive device 105 and vertical lrudder 82 through post 84, for the reason that when volplaning no power at all is required after a certain angle of downward inclination has been reached. As in case of operation from the pressure device 105 and from the rudder 82. however, the degree of operation of the throttle 142 and hence of the change in the propelling power, is proportional at all times to a function of the movement 0f control lever 140.

Such is the present embodiment of the system of my invention. Under this system, due to the government combinedly by variations in wind pressure or air rushwand variations in the position of the craft from normal with respect to the earth, and due to the interrelation of the operation of the various elements of the system with the pressure responsive device and with each other, the degree of unbalancing under disturbing forces is comparatively small, and while response is rapid, positive and accurate, it is ,vet gentle and easy. `With this system installed, an air craft can be operated by a mere novice with practically no prior training.

lVhile the automatic mechanisms operate, due to the interlocking and limiting devices, it is impossible for one to make unsafe control movements or to get the craft into unsafe positions. moved always precisely the proper vamounts and are retained in their operated positions for a length of time exactly that necessary to establish the corrective movement of the craft. The craft is also checked at normal automatically. The action of the automatic devices is far more accurate than the bestA Judgment of the most experienced aviator.-

The aviator cannot make dangerous turns under adverse conditions of unbalancing and speed. He cannot jam the control mechanisms in his attempts to make such turns. He cannot point his craft either upwardly or downwardly at too great angles, and it is thus impossible for him either to stall his machine or to get it pointed downwardly sofar that its recovery from the approach to` the vertical position is impossible. Nor is it possible forhim to' point the craft upwardly after automatic action has set the craft for safe descent on failure of power or other below normal pressure conditions. During all these operations the speed of actuation of the balancing devices, the amplitude of 4movement thereof, and the initial angle of bank' are automatically adjusted precisely to the right value to meet the conditions existing at any instant. Also autoinatically a far more efficient use of propelling power is had, the propelling power not only being automatically cut off when volplaning, but adjusted to suit the demands at The balancing rudders are vso ' Vany way from its generic spirit. 2o'

any instant, being progressivelyyaried when soaring flight sets in and` at all times subJect to complete removal by manual operation of the aviator. And throughout the system,

vices and of the other interdependent ele;

ments ofthe system surpasses incomparably any means of manual control at present known to the art. n I

It is obvious that the system of my invention may be given many forms other than that herein disclosed without departing in The reason for this is found in two facts, the rst of which is that the method of operation and control of an air craft as exemplified in the use of the system I have disclosed, is broadly new in each of several respects which will be pointed out in detail in the annexed claims. The second fact is found in the well. known versatility in the engineering profession in the production of a given device or system of devices in any one of a number of ways without departing in any wisefrom the generic'spirit of cooperation of the elements thereof. I likewise desire to cover in the annexed claims all embodiments of my invention which may fall within these limits. f

It is obvious that my system `may be used in part or in whole, it being quite feasible t0 omit one or many parts of the system without interfering with the performance of the functions of the other parts, though of course the advantages gained through the combination and interoperation of the parts omitted with the parts retained will be lost. Thus for instance it is possible to omit altogether the longitudinal balancing mechanism 117, yet retaining the pressure responsive device 105 and its-interconnections with the elements of the lateral balancing mechanism 10+l1-/ So also it is quite practicable to omit the connection of any elementof the system to pressure responsive device 105 withoutimpairing the functions of the remaining elements con-y nected thereto. Thus connection to leverl 151 and the throttle 142 might be `omitted in certain cases, the then free end of lever 151 being secured pivotally in any suitable manner. l So also for example the connection of device 105v to the block 157 on lever 87 may be omitted without impairing'the functions of the remaining connections, and so on throughout the system.

Furthermore as far as the system per se is concerned, it is possible for the versatile engineer to substitute for one element of position under such conditions to the end 66.'

the system o-f my invention another element ofthe same type already known to the art without departing from the spirit of my invention,` or changing the functioning of the element for which substitution is made. Thus as far as the rest of the system is concerned, a different form of pressure vane 60-60 may be used.v One such form is shown in Fig. 3 herewith. The vanes 60-60a of Fig. 3 differ from the vanes 60-60 of Fig. 2 and Fig. 1A in that the inclination of the opposite ends 62 and 63 is the same .on opposite sides of the axis 61. Thus the wind pressure exerts a lifting force on the entire length of the vane. As before however the end 63 is of greater area and weighty than the end 62 and hence the overbalancing wind pressure is on the end 63. Also the vanes of Fig. 2 are mounted on outriggers 175 entirely free from the horizontal projection of the main planes 176 of the craft whereby upwardly and downwardly directed pressures may act freely upon both ends of the.y vane, while in the case of the type shown., in Fig. 3, the .axis 61 is on the outer edges of the planes 176 whereby the inner ends 62 of the vanes 60 and 60a are within the horizontal projection on the planes. The effect of this is to secure more eicient action under upwardly and downwardly directed wind pressures, `the end 62 being shielded from such wind pressures and thus does not act in op- So also a parabolically curved lifting surface 108 may be substituted for pressure responsive device 105 as previouslyv described, and with the same results when incorporated. in the system. As far as the system is concerned,` the pressure responsive devices illustrated must be taken as illustrative of a type.

en pressure responsive devices are departed from, it is readil apparent indeed that any gravity controlled or gyroscopic standard of position may be used in lieu of the pressure responsive device in the same manner as the same are used widely today. The great advantages of the pressure responsive control will be lost, of course, but the system will not be. rendered 'inoperative'. The essential difference will lie in the fact that there will be no anticipation of unbalancing and no advance correction, correctiontaking place only upon unbalancing movement of the craft.

As regards the power operated mechanism 10--11 and 117, obviously primary and secondary motors may be combined with the results herein attained in a number of ways. The valve mechanism between the primary and secondary motors 10 and 11 may take a variety of forms. The valve 17 as shown is not a balanced valve, but a balanced valve maybe used if desired. 1n the present 1nyiso 

